Devil Versus the World
by Aesix
Summary: [666] gave him two choices: End the world or Become the last Devil. However, why did the sacrificial choice seem wrong? Why did he have to be alone to face the world—his loved ones? As the last devil, Issei fought the blissful world, not to protect himself, but to save it —Boosted Gear? Definitely. OP? Yes. LessPerverted LastDevil—Issei [I]
1. Dreams x Degenerate

[ **Spoilers** ]

* * *

"Have you ever suffered sinful regret?  
They say it kills like a blissful cigarette.  
Even in the name of righteousness,  
For those to live on without knowingness.

Only to be shoved,  
By my beloved.  
Am I allowed to grieve?  
With my hefty heave?  
Can I?  
I'm not the smartest guy,  
But, without cut, I know,  
I chose the right 'shadow.'  
I mean, at least,  
They didn't have to be deceased.

I am the 'terrifying' incarnation of sin, The Devil.  
I am the undying damnation who cannot yet settle.  
With that fact, I am too greatly hated.  
It's funny, I may just be fated,  
To be hurled,  
Into a world,  
Where I am incarcerated,  
As all great Seven Sins.  
Yet, this is where it... _begins_."

* * *

.

\- :|: - **Dreams x Degenerate** \- :|: -

.

... _  
W-Why am I here?_

The distorted space filled with multitudes of all kinds of light vibration. It seemed like a vivid dream yet bland with nothingness. It was the Dimensional Gap, the former home of the Infinite Dragon God, Ouroboros, or [∞], and the vacant home of the True Red Dragon God Emperor, Dragon of Dragons, or [ **DxD** ].

He tried to summon the [Boosted Gear], but to no avail. He had to leave; he couldn't stand the Dimensional Gap for it would rip him into nothingness, as he was still _weak_.

— _!_

Then suddenly, the surrounding area, for as far his sharp eyes could see, became pitch black.

 _W-What?_

What could shift what was between a huge mass of worlds so quickly, so easily? The "plane" that wasn't governed by time, or affected by the laws of space? Changing what shouldn't have existed?

His answers came with sense of dread that overcame him. It was unlike anything he had even felt, which may be that way since he was powerless to fight. It was on par with overwhelming power from [ **DxD** ] or [∞], which also cause his same numbness at their full bluntness, yet the vileness it radiated was unmatched. There was only one thing he could think of, something even he couldn't help but despise, despite befriending the other two beings that matched it potentially.

 _T-Trih-_

 _YoU aRe CoRrEcT, sEkYiRuUtEi_

His eyes widened, but didn't move. He knew he couldn't do anything. He was utterly useless without his [Sacred Gear].

 _NoW, nOw, DoN't FeAr Me. I hAvE a PrOhOsItIoN fOr yOu._

The voice was as sinister as it was, oddly, friendly. It felt as it were the both the angel and devil atop one's shoulder when making a tough decision.

 _W-What is it?_ Issei, despite his question, felt as if he didn't want to know.

 _HoH? i ThInK yOu'Ll QuItE LiKe It._

The thought of him liking anything that disturbed his peace... well, it was rather horrifying, he wasn't a battle-freak, like Vali after all. He may be perverted, but he wasn't _that_ crazy.

 _I kNoW tHe PlAn._

What plan? Was there a plan to cure his inability to see _oppai_? Issei wanted to ask, but decided to withhold his questioning, like a servant meeting its new master. However, he was sure that Trihexa, or [ **666** ], could read his mind.

 _It UsElEsS, yOu KnOw. EvErYtHiNg Is UsElEsS._

 _What was useless?!_ He felt so annoying without knowing for the first time in his life, without seeing breast anymore! The being talking to him could bring, and _was_ bringing, the end of the world—the end of boobs! Why couldn't he have a fighting chance? Why did he have to choose?! Why was he _STILL_ useless?!

 _HoW NoBlE oF tHeM tO **SaCrIfIcE** tHeMsElVeS tO wEaKeN mE, tHoSe CoCkY "lEaDeRs." It'S uSeLeSs._

His stomach harshly pitted, and his eyes widened once more at the sudden revelation. Even if he didn't know who would be sacrificing themselves, he knew that at least some people who would be a part of it. Especially, Sirzechs and Serafall, who would fight to protect their sisters and, by extension, the devil's populace and the rest of the world.

 _..._ Issei didn't respond. He could barely process what the creature had confessed. If it was useless, if _he_ was useless, what was the point? Ophis wasn't at full strength and Great Red rarely left his domain to do anything if at all. His newest form, [ **D∞D** ], could barely take on _one_ Super Devil with him unable to fight after. What good was it to fight against something that could shrug off attacks from _multiple_ Gods, Super Devils and other powerful beings like it was nothing? That was why no one bothered Great Red, after all.

 _SiLeNt I sEe._

The brutal creature paused.

 _ChOoSe WiSeLy, In—WhAt YoU hUmAnS cAlL 3-60's—ThReE mInUtEs._

The aura around Issei felt as if it wanted to choke him. His ears began ringing and his eyes blurred with the sense of asure and easy death. It was odd feeling that way. His deaths were always... so _troublesome_.

 _EvErY dEvIl ReVeRtInG bAcK tO **nOrMaL**. EvErYoNe WiLl LoSe ThEiR mEmOrIeS oF yOu Or EvEr BeInG a DeViL, aNd YoU bEcOmE [_ _ **Sin**_ _]_

 _Or!_

 _ThE SuIcIdE gRoUp FaCeS mE iN vAiN aNd I dEsToRy_ _ **ThIs**_ _wOrLd, FiNaLlY._

The voice changed into someone familiar, as if it was trying to mock him, effectively so, though without rage.

 _Hurry and choose, Issei-kun!_

Irina's voice echoed into the depths of the black oblivion. It startled him into flinching harshly. He hadn't expected the being into taking one of his beloved friends' voice. It was so... similar; he couldn't find a fault in its speech or tone that wouldn't have made it Irina's voice. Vivid images of her repeating the words, of her disappearing because the chance that second choice outshone the former's success and with the former—could he live without them?

A gut feeling told him he was forgetting something, something so important, he felt as if the first choice wasn't the right choice. But, he really wanted to select it, as it was something he would most definitely would easily and instantly give up himself to let everyone live. However, he didn't know what it was that he was forgetting.

Issei didn't know it, but he would be giving up his freedom to live in somewhat peacefulness as he was. He, as last stain of pure [ _ **Sin**_ ], would have to live knowing that the ones he saved would only hunt him as if it were some kind of sick sport. And he would be the only one to know of it, and his great sacrifice.

And that if failed to live, Trihexa would devour the world.

But, he would at least be saving everyone, right? If he could hold out, that was. It was an easy task, right?

The hold around him loosened and he was left to sputter for air on the sudden surface beneath him. The answer was obvious, if he wanted to save everyone, it was the former.

However, what if Trihexa was lying? How exactly does one change devils into angels or a fallen?

—What was holding [ **666** ] back from killing him at that moment?

 _W-Why are you giving me a choice?_

Issei swore he could feel the beast grinning as time was running out.

 _It'S bEcAuSe It'S fUn WaTcHiNg ThE "HeRo"_ _ **FaLl**_ _!_

It was mocking him for Issei felt like Trihexa was withholding information, _lying_. However, Issei, he knew that Trihexa wouldn't dare to tell him anyway.

He didn't know why but oddly, at its words, an "image" of God appeared into his mind. God died to seal away the beast, right? But did Trihexa also give the God a decision like his, then? But, nonetheless, it furthered his doubt, what if, though he didn't know what actually was at stake, he couldn't get them to fall in love with him again? What if he couldn't touch, and still couldn't see their beloved chests? He still wanted to see Koneko's breast grow!

However, he didn't know how powerful his presence in the world was. He didn't calculate that if no remembered him, or never remembered being a devil (if they were), then—

 _OnCe YoU fALl, I'lL dEvOuR yOu ThEn ThE wOrLd!_

Issei was harshly taken aback. It wasn't by the threat, but how quick the voice changed, and whose voice it was.

 _It's so much fun!_

It was... Rias' voice.

 _Now..._

Tears came to his eyes. He hoped he chose the right choice. _...Would they, truly, forget_ — _ **me**?H_ e never thought that hard before. But, his choice would change the whole world, so which was the right? Why did he have the right?

 _Perhaps, this time... I can... Maybe I_ —

 _ **CHOOSE**_ _!_

 _I-I choose_ —

\- :|: - **Dreams x Degenerate** \- :|: -

\\_(◕﹏◕)~

* * *

 **Vorpal** : _I'm not supposed to be working on this. But this story was really bothering me, and wouldn't leave me alone for the longest of times, especially after reading Vol. 21._ _Ugh,_ _that_ _volume..._ (ι´Д｀)ﾉ ┻━┻

 _This **will** include various OCs.  
_ _- Grace Sellzen {F} Priest/Warrior-Nun Human  
_ _A certain psychopath's sister, searching for the said psychopath. However, is he still that "psychopath?"  
_ _[Innocent Bro-con/A bitter reminder of Asia] (She seems like fun, lol)_

 _...This is just one of them..._ _  
_

 _I like short prologues... (I'm lazy)_ (¬_¬) _And I'm not too sure how to begin this story._  
 _Oh and this story doesn't follow my previous one-shot. I just so happen to finish them both around the same time.  
Editing: Some? An hour's work? Yes._

[Words: 1,666]

"Have a Nice Day"  
-Vorpal

What if God's choice was to rid all Devils?  
Let's see if it happens?

Lol, not.

I forgot this but this story was in originally inspired by:  
" **The Devil is a Part-Timer!** / **Hataraku Maou-sama!** "

* * *

\- :|: - **Surge x Spurious** \- :|: -


	2. Surge x Spurious

" _I am the 'terrifying' incarnation of sin, The Devil._  
 _I am the undying damnation who cannot yet settle._  
 _With that fact, I am too greatly hated._  
 _It's funny, I may just be fated,_  
 _To be hurled,_  
 _Into a world,_  
 _Where I am incarcerated,_  
 _As all great Seven Sins._  
 _Yet, this is where it... begins._"

* * *

"Talking" (Normally)  
 _Thoughts/Talking in the Dimensional Gap  
_ **TaLkInG** (Trihexa/Sin Form)  
[ **Talking** ] (Ddraig)  
:|Talking|: (Communication Spell, Phones, etc.)

.

\- :|: - **Degenerate** **x** **Surge** \- :|: -

.

Blinking, Issei found himself still within the Dimensional Gap. However, what caught his eyes was the _Beast_ before him. What gave the _Beast's_ name away, however, was the morbid aura it radiated; it was the same as the blackness he had spoken to. However, instead of blackness, Issei could make out a size that was larger than Great Red. It had seven necks, heads, tails and ten horns. It's body and limbs, if it was simply _that_ , was composed of various animals and beings covered in various spots with midnight black fur—quite fitting for its title, **The Forbidden Black Emperor Beast of Apocalypse**.

The seven necks shifted, moving the heads towards Issei's direction when noticing his shifting—awakening.

 **ArE yOu ReAdY?**

...Issei wasn't sure for what. Nonetheless, he nodded, albeit slowly, unable to find it in himself to speak in such a vile and suffocating aura.

 **HaH.**

That sound confused him.

 **Do NoT LiE tO mE. yOu WiSh To SeE yOuR lOvErS.**

Issei's voice came to him at that statement. He set aside the meaning the word of "lovers" and knew who _It_ meant.

 _Does that mean I can_ —

 **No.**

The Trihexa and _Its_ aura shifted around him, pushing him, jeering at him, laughing at him—mocking him with _Its_ many voices.

 **RiZeViM's MeMoRiEs SuRe ArE InTrEsInG.**

Offhandedly, _It_ mentioned Issei's antithesis. Hearing _his_ name, Issei couldn't help but have anger surge through him as an electric-blue fiery wisp materialized above a horn and flickered with what he supposed were images of Rizevim's memories. Even under the oppressive aura, Issei found himself unable to steady his anger at the almost bored mention of the Super Devil. It was Rivezim's fault that the whole world was in the mess in the first place! I-If Rivezim Lucifer didn't exist, none of his problems wouldn't even be considered. Vali—though Issei didn't necessarily _hate_ him—wouldn't have been born, sure, but most of the world's problems probably wouldn't exist!

 **I wOnDeR, wHaT wOuLd HaPpEn If I gAvE tHeM tO YoU.**

...What?

 **He NeVeR aCtUaLlY DiEd, Ya' KnOw? He WaS gOiNg To SiT iT oUt AnD wAtCh HiS wOrLd CrUmBlE.  
**

T-That sick Fuck! Issei couldn't believe it. After everything he has done, after he and the world has gone through, he still did **not** die?!

— **So I kIlLeD hIm.**

That revelation shocked Issei enough that his mouth fell open.

 **LeT's StArT.**

That was Trihexa's only warning before Rivezim's wisp entered him.

...Issei couldn't move, feel or _anything_. His senses were thrown into a loop, switch off and on at various and irregular periods. His vision blurred so the around him looked even more dream-like than ever. He wasn't sure what was happening until it happened. He tried to move, feeling sick as he felt cold, despite having a _flame_ enter his soul. He began shivering, in such a cold, he actually felt hot— _burning_ even. While his physical draconian body was, in all purposes, _dead_ , his mind went under a fissure attack, gaining memories that weren't his own as he felt to his knees, still shaking. Then, ultimately, he fell onto his face, looking as if he was having a vicious spasm.

 _He_ wasn't _Issei_ anymore.

Energy— _power_ —surrounded him but it wasn't his—or was it?

"I am Rivezim!"  
"I am strong? —Yes! Yes, I _am_ strong!"  
"But it was just so... _boring_."  
"Let's... Let's bring the— **END**."  
"HAHHAHHA—Cough—HAHAH!"

...Issei's eyes widen. Those words... they weren't his own but he couldn't help to _agree_ with them because at that moment, they were his _then_. He was confused as he was conflicted as to who he was. Anger was one of the main emotions that surged through him. There was no way that _he_ of all people would agree to such words! However, after that moment, he felt so— _relieved_ , like he was accepted something that made him _desire_ more. His hand twitched, but he didn't know it wasn't because the burning cold.

His mouth fell open, as a soundless scream echoed nowhere. His hand had become deformed and his inwards of his hands shifted so horribly that they burst—exploded—from his hand. Until it shot right back into gory mess where _his_ —whoever _he_ was then—hand should've been.

The hand's skin was now pale in spots that looked like scars. Some parts of his fingers weren't same size as they were before. Some were mutated in size or angle to look like a freak accident occurred.

* **Sppplliish** *

Just his hands, his entire body followed. His inwards became outwards; the _Beast_ watched on with a slight curiosity. As suddenly as it left his body, his gore returned, leaving patches of something—someone—in various parts of his body.

The _new_ person had two hair colors. Brown from the original body and, in many places, silver white after the transformation. _His_ skin tone was now either pale or a light tan in random places as if he had a odd skin deformation. His arms were of uneven sizes much like the fingers that was much like a prologue to this... _shift_. _His_ face had changed the most and that said a lot compared to the rest of his body. _His_ face was angular like Rivezim's but it still retained it's boyish look from the original _person_. However, that was until one would look at the deformed nose which _tried_ to combine the shape of the said persons' noses. The eyes were strange as they retained both colors in various spots, uneven between the eyes and one eyeball even had two pupils.

All in all, he was an abomination that was like... the _Beast_ , on a _much_ smaller scale.

 **ThIs... Is InTrIgUiNg.**

With a sick sense of curiosity, more wisps appeared atop its heads and shot forth towards the motionless _thing_.

Those wisps... They were his enemies, and, yet, they were his friends.

"Issei-senpai, I-I'm s-scared!" Gasper's vast devilish-energy pool had become his as his body went under another change among changes since he had not one _flame_ enter him, but seven.  
"Sword Birth!" Yuuto's skill and abilities had been engraved into him as hard as they been onto Yuuto.  
"Darling—Let's practice!" Xenovia's memories and affinity with swords were his. And _he_ was now _Five.  
_ "Issei-senpai, you pervert." He gained Koneko's desire and strength, his mental state thrown into fluctuation. _  
_"Ufufufu, Issei, you make me so... hot." Akeno's tendencies and amplitude for magic was now his, whoever he was then.  
 _"I-Issei!_ I w-want a k-k-k-kiss t-too!" Asia had also followed, awkward urges and grace appeared into him.

The last one stopped before him.

He, unsure who _he_ actually was, stared at the flickering wisp.

It showed _her_. Rias.

Her wings had been out as she had been practicing various aerobatics along with her Bael powers since she felt bad that Issei was almost literally carrying them in battles. However, about to jump, her wings— _exploded_ , causing her to yell in shock and pain as she fell. Disbelief had fallen upon her as her wide eyes stared at the morbid mess of her twisting and shifting wings. As suddenly as his own transformation, the gore leaped back and reconstructed then reconnected itself as angel wings. The memory began to fade into another as it ended with a wisp leaving her.

And with that, it entered him.

"Ise—I love you!" Just like the rest, he had become Rias and yet, feeling less empty—desiring more.

 **ThIs Is KiNdA fUn.**

Trihexa didn't let up and gave him no more warnings or pauses. One after another, wisps from the devils of the past, present and perhaps even future entered him. He had seen the Great War and yet, at the same time, he had only just been born. He had so much power, he didn't know what to do with it, and yet, he had barely any enough for a teleportation circle. He had been so corrupt, he started a Civil War among Devils, but so kind, he sacrificed everything he had to protect those who couldn't protect themselves.

He had become... **Sin**.

.

\- :|: - **Surge x Spurious** \- :|: -

.

Fading into consciousness, cold, barren from head to toe. Oddly, it didn't affect him, but the area around him barren like a wasteland, and ashes of something dead did. And the strange black aura that surround him, he barely noticed as it didn't affect his sight.

He swung his hand to dispel it since he usually did that either as he used or after using [Balance Breaker] but instead, the aura dispersed in the path of his arm and a black and mystical crescent-shaped slash drove forward.

" **...** **HuH**?" What exactly had he just done? He has never done something like that before. It was easy too, but uncontrolled.

He swung his other arm, feeling oddly encouraged as he imagined yet a bigger slash.

* **Vvrrrrmmm!** *

And bigger it was, as it tore a distortion into the brown sky. He was awed at his powers once more. Suddenly, he blinked as if he felt strange. Something was bothering him at back his mind.

* **Ffsssh!** *

A portal opened above him, allowing various winged beings to teleport. Issei stared as they surround him, white feathers littering the area around him. They seemed to hypnotize him with their strange and mystical dance.

Follow their white-winged counterparts, a storm of other winged beings arose from the horizon, somehow catching his attention. Their march was akin to a black wave as they came towards—him?

 _What's going on?_

A ray of light struck his way like lightning but was unable to penetrate his aura, leaving him unaffected. It caused him to look back towards the portal, watching three white-winged beings and one golden-winged and fairly familiar creature to appear.

" **M... MiChAeL?** " Everything, even the on-marching black wave, flinched at his words, and he, whoever he was, was oddly worried at the sight.

 _Where am I?_

No one said anything, and the lone angel with a golden back glanced towards the on-coming wave of similar beings. It seemed to Issei that they were waiting for the similar beings to reach them. Once the black mass came towards the Angels, a Fallen with black hair and a golden fringe left his group to meet up to the golden winged Angel, Michael. _Azazel-sensei..._ After moments of talking, Issei stood confused as they parted; Angels began to move to his right and the Fallen to his left.

"Aim!" The lone golden-winged person threw up an arm, as energy began collecting in its grasp. "Ready!"

 _They..._ Something occurred to him. _...don't remember?_

[ **!** ]

—His red eyes widened and a headache caused him to tremble, affecting his aura into flaring wildly. His vast blackness swallowed various Angels and Fallen. Their morbid screams failed to reach his ears but not their kin's ears. Many of them disregarded the wait for the signal and tossed colored spears.

[— **PARTNER! Get your power under control! NOW!** ]

 _...I can't..._

He, still unsure who exactly he was, was _trying_. He really was but it did nothing as he was still unused to his absurd amount of power. When he went to pull his aura in to stop it from swallowing more people—it did the opposite. Quickly, he had withdrew his hand and curled up. He was afraid of moving—hurting people by accident. He could only hope that they would leave him be.

[ **Partner! You are** — **Issei! You need to move!** ] A spear made of the combined efforts of the leaders of the Grigori, and God's Heaven struck against his vile aura. However, unlike the others, it actually pierced his black aura. Slowly, but surely, it inched closer.

[ **If you don't, you won't see... any of** **—them, like you wanted, right?** ] Ddraig's words finally gathered a reaction out of him. He flinched. [ **Look, I'm not like Albion, I can't filter power like him. However, I know someone who can help, alright?** ]

Slowly, his _true_ memories were beginning to resurface. He originally was Hyoudou Issei. Ddraig was his partner inside the [Boosted Gear].

 _I'm tired..._

Ddriag paused, hearing his partner's hollow thoughts. It lacked its usual emotion and conviction. He wasn't sure what exactly Trihexa had done to Issei as he had been unable to hear Issei's thoughts, memories for a while, but he got the gist of it. While he could do it now, it wasn't the right time to do so. Perhaps, later when they away from attacks. [ **Partner, you need to make a portal for "Familiar Forest." I'll tell where to go from there.** ] Ddraig sighed, hoping _she_ would help him. If not, then perhaps, they could find the nekoshou sisters. Nonetheless, Ddriag needed to help Issei to control, or at least, withhold his powers. Ddraig definitely knew how to do so as he also had done so with his vast powers before being sealed in a [Sacred Gear]. Although, not on the level Albion could do so, he would give his eternal rival that much.

 _A-Alright._

\- :|: - **Spurious x Prolix** \- :|: -

\\_(◕﹏◕)~

* * *

 **Vorpal** : _... Would you like to see an Anti-Hero Issei?_  
 _Originally, I wasn't going to do that, but it's plausible for Issei to act that way with what I'm doing anyway. I did do something similar to a favorite anime of mine, **Charlotte** as you saw with the whole clusterfuck of memories and powers, which is similar to Yuu's clusterfuck of powers. Hence— **Surge**._

 _So basically, every pure devil became either an Angel or Fallen. The rest returned to their state before being reincarnated. So Koneko, and Kuroka are pure nekoshou and everyone (Akeno, Yuuto, Asia, etc) else reverted. Hence_ — ** **Degenerate****.

 **Immediate** Pairing(s): _...Tiamat, Kuroka, Koneko, Kunou, Raynare, and perhaps, Akeno_

 _To be honest, I'd rather use OCs with SOME elements of other characters than use crossover characters, so please don't suggest any._

This _was_ the rewrite of **Not Angel, Nor Devil** , but the plot was changed due to lost documents and the latest translated LNs.

 _Editing: Some?_

 _...And it's actually harder to do the Trihexa speech thing than it looks. Perhaps, it's because I'm weird like that..._

[Words: 2,543]

"Have a Nice Day"

This story was in originally inspired by:  
" **The Devil is a Part-Timer!** / **Hataraku Maou-sama!** "


End file.
